Windows are one of the biggest barriers to energy-efficient houses.  It releases or absorbs a vast amount of heat that could be used to heat and warm the house. Researchers are now gearing up to develop smart windows that could play a vital role in energy consumption.  Researchers have come up with a material made from 95% air and 5% silica nanoparticles that are capable of preventing heat loss from windows. The material when placed between the two glasses is more insulating and long-lasting than traditional glasses. If researchers would be able to make this technology affordable, this could improve building efficiency and could reduce the carbon emission.